1. Field of the Inventor
This invention relates to optical information storage disks and to an apparatus and a method of forming additional machine readable code on prerecorded disks.
2. Background of the Invention
Optical information storage disks (optical disks) are now a common method of distributing a variety of information products. These disks include CD-audio, CD-ROM, CD interactive and digital video disk (DVD). It is desirable to include machine readable information on the disks in addition to the prerecorded information contained on the disk. Prior art devices and methods have been suggested to provide such information. However, the prior art methods are not sufficiently efficient and do not provide as much additional machine readable information as desired. See U.S. Pat. Nos. 4,961,077 (Wilson); 5,400,319 (Fite); 5,513,169 (Fite).